You can find Streams code examples in the Apache Kafka® and Confluent GitHub repositories.

The Confluent Streams examples are located here. These examples demonstrate the use of Java 8 lambda expressions (which simplify the code significantly), show how to read/write Avro data, and how to implement end-to-end integration tests using embedded Kafka clusters.

The Event-Driven Microservice example implements an Orders Service that provides
a REST interface to POST and GET orders. Posting an order creates an event in
Kafka, which is picked up by three different validation engines: a Fraud Service,
an Inventory Service, and an Order Details Service. These services validate the
order in parallel, emitting a PASS or FAIL based on whether each validation
succeeds.